Axial flow pump cavitation characteristic extraction method based on noise texture and bubble morphology comparison

Abstract

The invention discloses an axial flow pump cavitation characteristic extraction method based on noise texture and bubble morphology comparison. The method comprises the following steps that (1) axial-flow pump video data with cavitation bubbles is collected as an experimental group, axial-flow pump video data without cavitation under the same working condition is collected as a control group, eachframe of images of the working states of an axial-flow pump in the two groups of video data correspond, and background images are removed; (2) image frames of the two groups of video data are converted into grayscale images, and noise reduction treatment is carried out after the edges of the images are extracted; (3) image signal characteristics of bubbles in the experimental group are obtained according to the characteristic information of the two groups of images; (4) after filtering and denoising are carried out on the acoustic signal data of the experimental group, frequency domain analysis is carried out, and noise texture features are extracted; and (5) the noise texture features are compared with image signal characteristics of bubbles, and connection between the noise texture characteristics and the image signal characteristics of the bubbles is built. The purpose of extracting cavitation bubble characteristics of the axial-flow pump is achieved through mutual verification ofthe acoustic signal characteristics and the image characteristics.

Description

technical field [0001] The invention belongs to the field of axial flow pump signal processing, and in particular relates to a cavitation feature extraction method of an axial flow pump based on noise texture and bubble shape comparison. Background technique [0002] Fluid machinery, including pumps, hydrofoils, and axial flow pumps, etc., often produce cavitation and cavitation phenomena when operating under realistic flow field conditions. Due to changes in air pressure and water pressure in the flow field, cavitation is constantly born, growing and developing. , Collapse and other processes, especially the impact energy generated by bubble rupture in the process of collapse, under long-term accumulation, it will corrode the fluid machinery, and the decline in mechanical properties is inevitable. At the same time, the same fluid machine (such as axial flow pump) will produce different cavitation development conditions under different working conditions, such as cavitation ...

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Problems solved by technology

[0003] For example, the Chinese patent document with publication number CN102252748A discloses a method for extracting cavitation noise modulation features based on empirical mode, which overcomes the traditional The modulation feature extraction method is difficult to extract modulation features for short-term, non-stationary modulated cavitation noise data

[0004] At present, some achievements and theoretical foundations have been obtained in the analysis of cavitation characteristics purely by using acoustic signals, but the academic community still lacks a unified understanding of the mechanism of cavitation

At the same time, since the in-depth level of cavitation research does not match the broad application prospects of this research direction, there is an urgent need for a means to help scholars establish a reliable cavitation characteristic research method

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